Certain regulatory motor-vehicle lights such as low-beam lights or fog lights must project a light beam that is bounded at the top by a profiled cutoff. This profiled cutoff is shaped so as to prevent the drivers of other vehicles from being dazzled.
The profiled cutoff extends horizontally on the whole, which allows the reach of the beam on the side of the road on which oncoming vehicles are likely to arrive, for example the left in France or the right in the United Kingdom, to be limited while illuminating over a larger distance that edge of the road which is located on the other side.
To this end, the profiled cutoff for example contains two staggered horizontal plateaus that are connected by an inclined intermediate segment. The inclination of the intermediate segment is for example 15° with respect to the horizontal.
Moreover, it is sought to produce lighting modules having a narrow exit face that is elongate vertically, i.e. orthogonally to the horizontal plateaus of the profiled cutoff. Such a lighting module thus allows a lighting or signaling light function that has a small transverse bulk to be produced.
Furthermore, such a narrow-exit-face lighting module allows designers to produce a vehicle having a visual signature that is recognizable from a distance.